# Identify vistior by tracking url
**URL:** https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166
**Category:** Product Support
**Created:** [August 5, 2017, 9:06am UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166 "2017-08-05T09:06:33Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@deddy](https://forum.mautic.org/u/deddy)
#### Post date: [August 5, 2017, 9:06am UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166/1 "2017-08-05T09:06:33Z")
I have no clue what is it exactly “Identify vistior by tracking url”?
As it mentioned a Note: Email contact field have to be marked as unique indentifier and publicly updatable in Configuration.
How do I mark email as unique indentifier?
---
### Author:  [@deddy](https://forum.mautic.org/u/deddy)
#### Post date: [August 5, 2017, 9:06am UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166/2 "2017-08-05T09:06:33Z")
I have no clue what is it exactly “Identify vistior by tracking url”?
As it mentioned a Note: Email contact field have to be marked as unique indentifier and publicly updatable in Configuration.
How do I mark email as unique indentifier?
---
### Author:  [@deddy](https://forum.mautic.org/u/deddy)
#### Post date: [August 29, 2017, 3:26pm UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166/3 "2017-08-29T15:26:44Z")
Thanks Kuzmany
---
### Author:  [@Jergas](https://forum.mautic.org/u/Jergas)
#### Post date: [January 15, 2018, 2:56pm UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166/4 "2018-01-15T14:56:21Z")
Hi,
Is it possible to pre-populate a form with this method?
Cheers
Javier
---
### Author:  [@Jergas](https://forum.mautic.org/u/Jergas)
#### Post date: [January 15, 2018, 3:00pm UTC](https://forum.mautic.org/t/identify-vistior-by-tracking-url/9166/5 "2018-01-15T15:00:38Z")
The answer is here [https://mautic.org/docs/en/forms/manage\_forms.html](https://mautic.org/docs/en/forms/manage_forms.html)